1. Technical Field
The present invention relates to a switching module which includes a series-connected unit of a first flowing restriction element and a second flowing restriction element and a snubber circuit connected to the series-connected unit in parallel, the first flowing restriction element having an opening and closing function of opening and closing a flowing path of current, and the second flowing restriction element having at least one of a rectifying function of restricting the direction in which current flows and the opening and closing function.
2. Related Art
Generally, a power converter circuit generates high-frequency noise due to the change of a switching state of a switching element. For example, Japanese Patent No. 4455914 discloses a measure against the high-frequency noise. In this configuration, a conductor connected to a collector of a high-potential-side IGBT (insulated gate bipolar transistor) and a conductor connected to an emitter of a low-potential-side IGBT are opposed to each other, and a conductor connected to an emitter of the high-potential-side IGBT and a conductor connected to a collector of the low-potential-side IGBT are opposed to each other. Hence, the direction in which a current flows when the high-potential-side IGBT is turned on can be contrary to the direction in which a recovery current of a diode connected to the low-potential-side IGBT in anti-parallel flows. Consequently, parasitic inductance of the above conductors can be restrained, which decreases surge voltage.
However, since the structure of the above conductors is variously restricted by the cooling structure of the switching element, current capacities of the conductors and the like, the shape cannot easily be changed.